Packaging of aerosol products



W. MQONAN PACKAGING OF AEROSOL PRODUCTS 2 Sheets$hee Filed Jan. 27, 1964INVENTOR.

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W. MOONAN PACKAGING OF AEROSOL PRODUCTS 2 Sheets-Sheei Filed Jan. 27,1964 INVENTOR. A/ 44/AM MaaMaa/ Menu/Low 3 ATTOPA/EYS United StatesPatent 3,335,765 PACKAGING OF AEROSOL PRODUCTS William Moonan, ShakerHeights, Ohio, assignor to Sprayon Products, Inc, Bedford Heights, Ohio,a corporation of Ohio Filed Jan. 27, 1964, Ser. No. 340,261 11 Claims.(Cl. 141-20) This invention relates to the packaging of pressurizedproducts and more particularly to methods, articles and apparatuswhereby a product to be dispensed, such as a paint, lacquer or othermaterial that is to be dispensed in aerosol form, can be injected intoan aerosol can already contains the liquified propellant gas that isused to discharge the contents of the can. The invention is describedherein particularly as it is adapted to loading paints, lacquers,varnishes, enamels and like coating materials (hereinafter referred toas paints and the like) into aerosol cans, but it is to be understoodthat theinvention may also be used in connection with other materials,such as insecticides, lubricants, medicines, cosmetics and the like ifthat is desired.

The present application relates particularly to an apparatus in thenature of a manually operated pump for forcing material to be sprayedinto an aerosol can that has previously been charged with a liquifiedpropellant gas.

The application also relates to a disposable liner for use in such anapparatus, which is provided so that the apparatus requires a minimumamount of cleaning after use or when it is desired to change from onematerial to another, for example one color of paint to another.

Reference is hereby made to my copending application Serial No. 640,765,filed March 29, 1967, for Method and Article for the Packaging ofAerosol Products, which contains claims directed to the method and tothe aerosol container disclosed herein.

Paints and the like are sold widely in aerosol cans. Conventionally,these materials are packaged in aerosol cans by placing the requiredamount of the vehicle and solvents for the paint or the like, togetherwith the pigments, into aerosol cans that have open tops. Then,according to one method, the open top of the can is closed and sealed bya closure member that carries the valve that controls the discharge ofthe aerosol spray from the can. Thereafter, the required amount ofliquified propellant gas, such as dichlorodifluoromethane or otherappropriate halogenated hydrocarbon is added to the can by forcing it inthe liquid state through the discharge valve. According to anothermethod, propellant gas is added to the cans in the liquid state throughthe open tops of the cans and then the closure member carrying thedischarge valve is applied to the top of the can. Both types ofoperations require rather complex and expensive equipment.

The demand for paints and the like in many different colors and shadesas well as the practice of custom blending of colors makes itimpractical for the usual dealer, such as a paint or hardware store, tokeep in stock loaded aerosol cans containing paints of all of the colorsand types that may be requested. Also, aerosol paints and the like areused widely for the touching up of damaged aeras of automobiles,appliances, furniture and the like; if an article has been finished in acolor blended to suit an individual customers preferences, it isdesirable to furnish the customer with an aerosol can containing thespecially blended paint so that the customer can touch up damaged areasit necessary. There are also other products involving specially preparedformulations that could conveniently be dispensed from aerosol cans, butwhich are not so dispensed at present because, so far as I am aware,there is no economical and convenient way presently available 3,335,765Patented Aug. 15, 1967 for filling one can or a few cans to meet aparticular requirement.

Accordingly, general objects of the present invention is the provisionof a simple and economical apparatus whereby a material to be dispensedor one or more ingredients of a material to be dispensed can be injectedinto a closed aerosol can'that contains the propellant gas that is usedto discharge the material and, if desired, one or more ingredients ofthe material. Another object is the provision of such an apparatus thatcan be operated by hand. Another object is to provide such an apparatusembodying means whereby the quantity of material injected into the canscan be accurately controlled. A further object is the provision of suchan apparatus in which the necessity for cleaning the apparatus whenchanging from one material to another is minimized if not entirelyeliminated.

Other objects and advantages of the invention will become apparent fromthe following description of a preferred form thereof, reference beingmade to the accompanying drawings in which:

FIGURE 1 illustrates an aerosol can of a well-known type that is adaptedto be filled by the method and apparatus of the present invention;

FIGURE 2 is a perspective illustrating an apparatus made according to apreferred form of my invention with an aerosol can in position forfilling therein;

FIGURE 3 is a perspective, on a slightly smaller scale, illustrating theapparatus of FIGURE 1 with some of the parts disassembled;

FIGURE 4 is a vertical sectional view, on an enlarged scale, through theapparatus of FIGURE 2;

FIGURE 5 is an enlarged section detail showing the top of a can such asillustrated in FIGURE 1 and embodying a known aerosol discharge valve,and illustrating the engagement between the apparatus of the presentinvention and the valve;

FIGURE 6 illustrates one of the disposable cylinder liners used in theapparatus;

FIGURE 7 is a fragmentary section taken along line 7-7 of FIGURE 4, andFIGURE 8 is an elevation showing the same parts;

FIGURE 9 is a fragmentary vertical sectional view showing an apparatusembodying a modified form of piston that is enclosed in a disposablesleeve.

The apparatus of the present invention is particularly adapted to injectmaterials into aerosol cans of conventional types, for example, canssuch as illustrated at 10 in FIGURE 1. Can 10 has a cylindrical body 11and an upwardly convex bottom 9, the bottom being convex in order togive it strength to withstand the pressure within the can. The upper endof the can body 11 is reduced in diameter as at 12, leaving an openingwhich is closed by a closure cap 13 that is crimped and sealed to theupper edge of the can body.

Cap 13 supports a discharge valve 14 that may take any convenient form,a preferred form of valve being illustrated on an enlarged scale inFIGURE 5. The valve is normally closed but may be opened by means of aplastic actuating cap 15 having a hinged flap 16 that engages a valveactuating pin 17; when the flap is depressed by the users finger the pin17 is also depressed and opens the valve as explained in greater detailbelow. When the flap is depressed, the pressure of the propellant gaswithin the can causes the contents of the can to flow upwardly throughthe flexible plastic dip tube 18 and the .valve 14 and finally to bedischarged from a spray orifice 19 carried by the cap. Upon release ofthe flap, the valve automatically closes. When cans of this type arefilled at the factory, the material to be sprayed, such as a paint orthe like, is placed in the can before the closure cap 13 is secured tothe top of the can. Then as noted above, the closure cap can be securedto the can and the propellant in liquified form forced through the valveinto the can or the propellant in liquified form can be added to the canbefore the closure cap is secured to the top of the can. In eitherevent, the level of the material in the can is then approximately at thelevel of the dotted line A in FIGURE 1. After the closure cap 13, towhich the valve 14 has been secured, has been crimped to the top of thecan and the filling of the can completed, the plastic actuating cap 15carrying the actuating pin 17 is placed on the upwardly projecting body20 of the valve 14.

According to the present method, cans intended for filling in accordancewith the present invention are charged with a desired amount ofliquified propellant gas, such as dichlorodifiuoromethane and, ifdesired, one or more other materials, at the factory preferably beforethe cap 13 is crimped to the can. The can is closed by the cap 13carrying the valve 14. The aerosol package then can be completed at anysubsequent time by injecting additional material into the can throughthe valve 14, preferably by the use of the apparatus of the presentinvention. In typical formulations, the liquified propellant gas isabout fifty percent by weight of the contents of the can, but since thepropellant has a substantially greater specific gravity than the usualpaint or the like, in typical formulations the liquified propellant is alittle more than forty percent by volume and the product a little lessthan sixty percent of the contents of the can. According to thepreferred method, in the case of some materials a substantial portion ifnot all of at least one of the constituents of the material to bedispensed is also placed in the can at this time; i.e., some or all ofthe ingredients that are common to a family of materials to be dispensedmay be loaded into the cans at the factory, leaving only the variablematerials and perhaps portions of the common materials to be added atlater times as required. For example, in the case of most paints and thelike, part or all of the solvent (the term solvent as used hereinincludes blends of two or more solvents) for the paint or the like mayalso be placed in the can; this is ordinarily done before the can isclosed and before the liquified propellant gas is added to the can; theliquified gas is added either before or after the can is closed by a cap13 carrying a valve 14. Loading the solvent at the factory isadvantageous because paints and the like as ordinarily sold must bereduced by the addition of solvent before they can be properly sprayed.By adding, at the factory, the solvent that would otherwise have to beadded to the paint or the like as supplied by the manufacturer to reduceit to spraying consistency the following benefits accrue: (1) If solventwere not added at the factory, it would be necessary to reduce the paintor the like as it comes from the paint manufacturer with a solventbefore injecting the paint or the like into the aerosol can. Thepreferred method eliminates this step. (2) The correct amount of solventcan be added by automatic machinery under carefully controlledconditions in the factory. (3) The use of a correct solvent that iscompatible with the propellant gas can be assured. (4) The addition ofthe solvent reduces the vapor pressure in the aerosol can from, forexample, about 70 pounds per square inch gage withdichlorodifluoromethane to about 50 to 53 pounds per square inch gage.This reduction in pressure makes it possible to use less expensive andmore readily available cans than would be required for the higherpressure and lessens the pressure that must be employed to inject thebalance of the material into the aerosol can through the dispensingvalve. (5) Loss of solvent by evaporation during the operation offinally filling the cans is minimized. (6) The volume of material thatmust be injected into the aerosol can through the dispensing valve issubstantially reduced.

A typical 6 ounce aerosol can containing a lacquer to be sprayed willcontain about 42 gm. of lacquer as supplied by the lacquer manufacturer,42 gm. of solvent and 84 gm. of dichlorodifluoromethane. The materialshave different specific gravities, the liquified propellant having thegreatest. By volume, the propellant is a little more than 40% of theliquid content of the can, the solvent a little over 30% and theunreduced lacquer a little less than 30%. With such a formulation,dotted line B in FIGURE 1 shows the approximate level of propellant andsolvent. If propellant only is placed in the can at the factory, thelevel is about as indicated by line C. Line A indicates the level afterthe lacquer has been injected into the can. A typical 6 ounce can of aspray enamel contains about 55 gm. of enamel as supplied by themanufacturer, about 30 gm. of solvent and about 84 gm. ofdichlorodifluoromethane. Here, the dichlorodifluoromethane constitutes alittle over 40% by volume of the liquid content of the can, the solventabout 22% and the enamel a little more than 35%. It will be seen that inboth of these typical cases, if the solvent is added to the can at thefactory the amount of material that must be injected into the can tocomplete the product is substantially reduced. Furthermore, the greaterviscosity of the paint or the like before it has been reduced tospraying consistency makes it easier to inject into the can and reducesleakage problems as compared to the same material that has been reducedwith the required amount of solvent.

It is evident that cans containing propellant alone or propellant andsolvent or other ingredients that are common to a family of materials tobe dispensed are complete articles of manufacture that can be sold topaint dealers, hardware stores, large users of aerosol products andothers to be used in the production of complete pressurized packages ofmaterials, ready for use. The actuating cap 15 and the pin 17 are notslipped over the body 20 of the valve before the cans are shipped fromthe factory. Instead, the cans are supplied to the users of the presentinvention without the actuating caps and pins in place, these beingsupplied separately. The cans then can be made into complete aerosolpackages simply by injecting the particular material to be dispensed,including any required additional solvents, dispersing agents, vehicles,or the like, into the can through the valve 14 against the pressurewithin the can and putting the actuating caps and pins in place on thevalve bodies.

The present invention provides a relatively simple and economicalapparatus whereby paints and the like, as well as other materials to bedisepnsed from pressurized containers can be injected easily and rapidlyinto cans of the type described above. As shown in FIGURES 2, 3 and 4 ofthe drawings, an apparatus according to the invention comprises a basemember indicated in general at 25 and having diverging leg portions 26that are provided with vertical ribs 27. The n'bs merge into a curved,substantially semicylindrical, upwardly extending portion 28 at theforward end of the apparatus where the legs 26 are joined together by aweb 29. The web provides a support for a can 10 disposed within therecess provided by the upwardly extending portion 28, in position to befilled. The rear ends of the legs 26 and the forward end of the curvedportion 28 are provided with feet 30 for supporting the apparatus on acounter, bench or the like.

The base 25 is arranged to support a cylinder and piston mechanism thatis adapted to be actuated by hand to force material into a can 10against the resistance offered by the valve 16 and against the pressurewithin the can. To this end, a horseshoe-shaped member 31 is secured tothe top of the upwardly extending portion 28. Member 31 is provided witha circular recess 32 that is dimensioned to fit the supporting flange 33of a cylinder member 35. Cylinder 35 has a main, working bore 36, aconical, tape-red portion 37 and a depending, externally taperedconnecting portion 38 having a bore 39 that is adapted to surround theupwardly projecting body 20 of valve 14.

The cylinder 35 is held in position within the recess 32 of thehorseshoe-shaped member 31 by -a pair of locking levers 40 that arepivotally mounted on the member 31. These may be positioned in a lockingposition, as shown in FIGURE 2, where their ends 40a overlie the uppersurface of the flange 33, or in a release position as shown in FIGURE 3where the levers are swung toward each other so that their ends 40aclear the flange 33 to permit the entire cylinder mechanism to beremoved from the support. At the upper end of the cylinder 35 there isan outwardly extending flange 41 that supports a cylindrical member 42that constitutes a reservoir for material to be injected into the can10.

In order to make it unnecessary to clean the cylinder 35 or thereservoir 42 when changing from one material to another or from onecolor or shade of paint or the like to another, as well as to providefor a substantially fluid-tight connection between the cylinder 35 andthe valve, disposable liners 45 are provided for insertion into thecylinder 35 and the reservoir 42. As shown particularly in FIGURES 3, 4and 6, each liner comprises a reservoir portion 46 terminating in asloping bottom 47 that is joined to a more steeply sloping conicalportion 48 that is connected to a downwardly extending cylindricalportion 49. The liners are preferably composed of a translucent materialand when such liners are to be employed the wall of cylindrical member42 is preferably slotted as at 43 and provided with graduations 44 sothat the amount of material placed in the reservoir portion 46 can bedetermined with the required degree of accuracy. The cylindrical portion49 fits closely within the main bore 36 of the cylinder 35 andconstitutes, in effect, the working portion of the cylinder. At thelower end of the cylindrical portion 49 there is another inwardlysloping conical portion 51, that joins with a connecting portion 52 thatfits closely within the reduced bore 39 of member 35 and surrounds thebody of the valve.

In order to make a substantially leakproof connection between theconnecting portion 52 of the liner 45 and the exterior of the body 20 ofthe valve 14, the interior of the connecting portion 52 is provided withan inwardly projecting annular rib or head 53 (see FIGURE that isdimensioned to make sealing engagement with the cylindrical exteriorsurface of the valve body. Since the liners are preferably composed ofpolyethylene or another similar slightly yieldable plastic material, andsince the connecting portion 52 is supported against expansion in radialdirections by the bore 39 of cylinder 35, the rib 53 can be dimensionedso that it must be deformed slightly when it is pushed over the body 2t)of the valve. In this manner sufliciently high unitpressu-res can bedeveloped between the rib and the exterior surface of the valve bodysubstantially to prevent leakage around the exterior of the valve body,even under the rather high fiuid pressures that are required to forcematerial into the cans.

The reason that substantial pressures are required will be evident fromthe consideration of FIGURE 5 which shows the apparatus in use inconjunction with a valve 14 of a known type that is described andclaimed in United States patent application Ser. No. 157,296, filed Nov.22, 1961, now patent No. 3,182,864 in the names of John G. Ellis, VernonC. Groth and John Hall. The valve body 26 has an internal bore 55 thatcommunicates with the dip tube 18. A valve member 56 is disposed withinthe bore beneath a valve seat 57 that is formed in the bore. The valvemember 56 is urged into sealing engagement with the valve seat 57 by thepressure of the propellant gas within the can and also by the forceexerted on it by a valve spring 58. The valve is thus in the nature of acheck valve that is normally closed to prevent discharge of the contentsof the can, but which can be opened by external fluid pressure in excessof the pressure within the can, thereby permitting material to beinjected into the can. The valve member 56 is shown in FIGURE 5 as beingdisplaced downwardly away from the seat 57; this'occurs when material isbeing forced into the can. In practice a pressure of several hundredpounds per square inch is required to open the valve and to force thevalve member 56 out of sealing engagement with the seat 57 against thefluid pressure and the force exerted by the spring. The reason for this,of course, is that the area of the valve member 57 exposed to pressureof the material being forced into the can is relatively small so thateven though the spring pressure is not excessive, the fluid pressurerequired to open the valve against the action of the spring and thefluid pressure within the can is substantial.

A piston 60 that is dimensioned to make a close working fit within theinner surface of the cylindrical portion 49 of the liner 45, whichconstitutes the working portion of the cylinder, is utilized to forcematerial from the reservoir 46 into the can 10. In the embodiment shownin FIGURES 3 and 4, the piston consists of a rod of uniform diameterthroughout substantially its entire length, the lower end of the rodbeing shaped as shown at 61 to conform to the conical tapered portion 51of the liner. The upper part of the rod is guided in a cylinder head 62that is detachably secured to the upper end of the reservoir 42 as bybayonet lock 63.

In order to provide for actuation of the piston 60, a bracket 65 issecured to the upright portion 28 of the base 25. An upwardly extendinglink 66 is pivoted to the bracket as at 67 and an actuating lever 68 ispivoted to the upper end of the link 66 as at 69. Lever 68 preferablyextends through a bifurcated portion 71 at the upper end of piston 60and is pivoted thereto by a removable pin 72. Preferably, the pin isprovided with a projection 72a (FIGURES 7 and 8) so that the pin canonly be inserted or removed when the keyhole slots 72b and 720 in thebifurcated end portion 71 and lever 68 are aligned, which occurs onlywhen the piston and the lever are in their uppermost positions as shownin FIGURE 7. A convenient hand grip 73 is provided at the free end ofthe lever. In use, this is grasped by the operator as shown in FIGURE 2.Downward movement of the piston is limited by engagement of the ends ofa ball 75, which is set into the piston, with the top of the upwardlyprojecting boss 76 of the cylinder head 62, but the ball is located sothat in the assembled apparatus the tapered portion 61 of the pistonengages the tapered portion 51 of the liner before the ball 75 engagesthe boss 76. Upward movement of the piston is limited by engagement ofasimilar ball 7 8 with the bottom surface of the cylinder head 62. Whenthe piston is in its upper position as shown in FIGURE 4, the taperedbottom end 61 of the piston is opposite the upper end of the cylindricalportion 49 of the liner leaving an annular clearance space between thepiston and the cylindrical portion 49 so that material in the reservoirportion 46 of the liner can flow into the cylindrical portion 49 whenthe piston is at the top of its stroke. When the piston is at the bottomof its stroke the lower tapered end of the piston engages thecorrespondingly tapered portion 51 of the liner. Thus each stroke of thepiston injects substantially all of the material within the cylindricalportion 49 of the liner into the can 10 through the valve 14 and bysuccessive strokes of the piston, substantially all of the materialinthe reservoir can be injected into the can.

As noted above, it is necessary to develop substantial pressure in orderto force material from the cylinder into the can. This is accomplishedwith the present apparatus without the exertion of undue force by theoperator, because in a typical device, the piston 60 has an area ofapproximately one half square inch and the lever system multiplies theforce exerted by the operator on the handle by about ten times. Thus, adownward force of about 20 to 30 pounds on the handle is ordinarilyentirely adequate to force material from the cylinder into the canthrough the valve 15.

At the upperlimit of its stroke, the piston clears the upper end of theworking portion of the cylinder and thus the piston itself acts as theinlet valve for the pump that is made up of the piston and cylinderassembly. The valve 14 acts as the outlet or discharge valve for thepump. In operation, on the downward stroke of the piston, the materialwithin the cylindrical portion 49 is forced into the bore 55 of thevalve body 20; leakage around the exterior of the valve body isprevented by the bead 53. The pressure of the material displaces thevalve member 57 downwardly against the action of the spring 58 and thematerial under pressure flows through the internal bore 55 of the valveand the dip tube 18 into the can 10. When downward movement of thepiston is stopped by engagernent of bottom 61 of the piston with theportion 51 of the liner, the operator raises the handle, lifting thepiston 60. When this takes place, the valve 14 closes immediately, thevalve member 56 moving into engagement with the seat 57 under theinfluence of the spring 58 and the pressure within the can 10. Raisingthe piston reduces the pressure within the cylindrical portion 49 and assoon as the bottom end of the piston 60 clears the upper end ofcylindrical portion 49 as shown in FIGURE 4, material flows rapidly fromthe reservoir 46 into the portion 49, ready to be forced into the can bya subsequent downward stroke of the piston. The liner is prevented frommoving upwardly with the piston by engagement of the upper edge of thereservoir portion 46 of the liner with the under side of the cylinderhead 62. The arrangement is such that by a comparatively small number ofstrokes of the piston 60, the required amount of material, such as thepigments, the vehicle, and some of the solvent of a paint or the likecan be injected quickly and easily into a can.

In operation, initially the cylinder head member 62 is removed from thecylindrical reservoir 42, the levers 40 are swung to release position,the cylinder 35 is removed from the horseshoe-shaped supporting member31 and the cylinder head 62 and piston 60 are completely separated fromthe cylinder. A clean disposable liner 45 is then inserted into thecylinder. The valve 20 of a can to be filled is inserted into the bore39, these parts ordinarily being wrung together because of the tight fitbetween them, the bead 53 making sealing engagement with the exterior ofthe valve body. Then the subassembly of the can 10, the disposable liner45 and the cylinder are positioned on the flat web 29 of the base asshown in FIGURE 4. The cylinder 35 then is locked in position by movingthe levers into locking position as shown in FIGURE 2.

The required quantity of the material to be injected into the can isthen poured into the reservoir 46. The material fills the cylindricalportion 49 and the lower portion of the reservoir 46, the amount ofmaterial being conveniently measured by the graduations 44, the level ofthe material in the reservoir portion being visible through the slot 43and the translucent wall of the liner. Next, the piston 60 is insertedin the cylinder, the cylinder head is secured to the top of reservoir42, the handle 73 is secured to the piston by the pin 72 and the handlepumped up and down a few times until the lack of resistance to thedownward stroke of the piston indicates to the operator thatsubstantially all of the material Within the reservoir 46 of the linerhas been injected into the can 10. The piston is then raised to itsuppermost position and the pin 72 Withdrawn to disconnect the pistonfrom the handle. As noted above in the preferred form of apparatus thiscan only be done when the piston is in its raised position and thusdisengaged from the cylindrical portion 49 of the liner. The levers 40are then swung to the releasing position and the subassembly comprisingcylinder 35, liner 45 and can 10 is removed from the horseshoe-shapedsupport 31. The filled can is then removed from the subassembly. This ispreferably done with the subassembly upside down to minimize the amountof material that may be left on the exterior of the valve and to preventsuch material from running into the closure cap 13. The assembly iscompleted by positioning a plastic actuating cap 15, carrying a pin 17,on the valve body 20. After this has been done, the valve is opened,with the can right side up, by means of the actuating cap until thesmall amount of injected material remaining in the dip tube 19 isdischarged. Finally, the can is turned upside down and the valve heldopen until gas, rather than liquid, is discharged. The package is readyfor use, except that with most materials the can should be shaken beforeuse in order thoroughly to mix the contents.

If additional cans containing the same material are to be produced, theoperations are repeated, using the same liner. Several cans can befilled without requiring a new liner 45.

If it is desired to inject a different material into a can, the liner45' is thrown away after use and a new one inserted in the cylinder 35.Also, the piston 60 is wiped clean, using a solvent if necessary. Sincethe piston is smooth and since only the lower portion of the pistoncomes into contact with the material to be dispensed, this is not adifficult task. The previously described operations are then repeatedwith the new liner.

If it is desired to eliminate substantially entirely the necessity ofcleaning any of the parts, a modified form of piston as shown at 60a inFIGURE 9 may be employed. In this modification, the lower end of thepiston rod is turned down to a slightly reduced dimension as shown atand a disposable sleeve 81, preferably composed of a plastic material,such as polyethylene, having a thickness corresponding to the reductionin radius of the piston 60 so that the external diameter of the sleeve81 makes a working fit with the internal diameter of the cylindricalportion 49 of the liner 45, is slipped onto the piston rod. Sleeve 81preferably has a flange 82 for ease in handling. The lower portion ofthe sleeve conforms to the shape of the end of the piston and the shapeof the portion 51 of the liner 45 so that the operation of the piston60a with the sleeve on it is just the same as the operation of thepiston 60 previously described. The only difference is that when it isdesired to change materials being injected into cans not only is theliner 45 replaced, but also the sleeve 81 is removed from the piston 60aand replaced with a new sleeve. With this form of the apparatus it isnot necessary, in ordinary circumstances, to clean any of the parts ofthe apparatus when changing from one material to another.

From the foregoing description it will be seen that the inventionprovides a simple and effective method and means whereby materials to bedispensed can be rapidly and easily loaded into aerosol cans whichalready contain the liquified propellant gas. The preferred method, inwhich not only the propellant but also another material are loaded intothe cans at the factory is particularly advantageous in the case ofpaints and the like. Aerosol cans made according to the invention andcontaining solvent as well as propellant are also of great utility,because cans containing the same kinds and the same percentages ofpropellant and solvent can be produced economically in large quantitiesand these then can be used at any subsequent time with available orspecially blended paints or the like to produce complete packagescontaining many different types, colors and shades of paints and thelike. The apparatus is relatively inexpensive to manufacture andrequires no particular skill to use. Since the apparatus does notrequire any complicated cleaning operations when changing from onematerial to another, it can be used effectively to produce one or a fewcans of various different materials, such as paints and the like ofdifierent colors, in a comparatively short time. The invention greatlyreduces the inventory of completed aerosol cans containing materialssuch as paints or the like that must be kept in stock by a dealer in orlarge user of aerosol products and gives the dealer much greaterflexibility and better ability to supply the needs of his customers.

Those skilled in the art will appreciate that various changes andmodifications can be made in the invention without departing from thespirit and scope thereof. The essential characteristics of the inventionare defined in the appended claims.

I claim:

1. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having adischarge valve at the top thereof, said apparatus comprising a baseadapted to support an aerosol can to be filled in a vertical position, acylinder member supported on said base, said cylinder member having avertical main Working bore communicating directly at its lower end witha vertical bore of reduced diameter that surrounds the discharge valveof a can disposed in the apparatus, a disposable liner removablysupported within said cylinder member, means for forming a seal betweensaid liner and said valve, a piston making a working fit within thatportion of the liner disposed in said main working bore, means forreciprocating said piston within said working bore and a reservoirportion disposed above said working bore and in direct communicationwith the upper end thereof for supplying material to be injected intosaid aerosol can to said working bore, the bottom end of the pistonclearing the top of the working bore when the piston is at the upperlimit of its travel whereby material will flow by gravity from saidreservoir into said working bore.

2. Apparatus according to claim 1 wherein said liner has a cylindricalportion fitting closely within the working bore of said cylinder memberand a connecting portion fitting closely within saidreduced bore of thecylinder member wherein said liner is adapted to make sealing engagementwith said valve, said piston making a working fit with the interior ofsaid cylindrical portion of said liner, said cylindrical portion andsaid connecting portion of said liner being externally supported againstinternal pressures by said cylinder member.

3. Apparatus according to claim 2 wherein said liner is composed of atranslucent material and said reservoir portion of said cylinder isprovided with a slot through which the level of material within saidliner can be observed, said reservoir portion of said cylinder beingprovided with graduations adjacent said slot whereby the amount ofmaterial within said liner can be determined.

4. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having anupwardly projecting, normally closed discharge valve at the top thereof,said valve being openable by external fluid pressure substantially inexcess of the pressure within said can, said apparatus comprising abase, a cylinder member removably supported on said base, said cylindermember having a main working bore communicating at its lower end with abore of reduced diameter that surrounds the said upwardly projectingvalve of a can disposed in the apparatus and a reservoir portiondisposed above said main working bore, a disposable liner removablydisposed within said cylinder member, said liner having a reservoirportion disposed within the reservoir portion of said cylinder memberand adapted to receive material to be injected into said aerosol can, acylindrical portion of less diameter than and disposed directly belowthe reservoir portion of said liner and fitting closely within said mainworking bore and a connecting portion of less diameter than and disposeddirectly below said cylindrical portion and fitting closely within saidreduced bore of said cylinder member and adapted to make sealingengagement with said valve body, a piston having a disposable sleevethereon making a working fit with the interior of said cylindricalportion of said liner, said piston extending through the reservoirportion of the cylinder and said disposable sleeve being of a lengthsuflicient to extend from the bottom end of the piston to a level abovethe normal level of material in the reservoir, and means forreciprocating said piston within said cylindrical portions of said 10liner, said cylindrical portion and said connecting portion of saidliner being externally supported against internal pressures by saidcylinder member.

5. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having anupwardly projecting, normally closed dischargevalve at the top thereof,said valve being openable by external fluid pressure substantially inexcess of the pressure within said can, said apparatus comprising abase, a cylinder member supported on said base, said cylinder memberhaving a main working bore communicating at its lower end with a. boreof reduced diameter that surrounds the said upwardly projecting valve ofa can disposed in the apparatus, a disposable liner removably disposedwithin said cylinder member, said liner having a reservoir portionadapted to receive material to be injected into said aerosol can, acylindrical portion of less diameter than and disposed directly belowsaid reservoir portion and fitting closely within said main working boreand a connecting portion of less diameter than and disposed directlybelow said cylindrical portion and fitting closely within said reducedbore of said cylinder member and adapted to make sealing engagement withsaid valve body, a piston making a working fit with the interior of saidcylindrical portion of said liner and extending through the reservoirportion, means for reciprocating said piston within said cylindricalportion of said liner, said cylindrical portion and said connectingportion of said liner being externally supported against internalpressures by said cylinder member.

6. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having anupwardly projecting, normally closed discharge valve at the top thereof,said valve being openable by external fluid pressure substantially inexcess of the pressure within said can, said apparatus comprising abase, a cylinder member removably supported on said base, said cylindermember having a main working bore communicating at its lower end with abore of reduced diameter that surrounds the said upwardly projectingvalve of a can disposed in the apparatus, a reservoir portion disposedabove said main working bore and a cylinder head member removablymounted on said reservoir portion, a disposable liner removably disposedwithin said cylinder member, said liner having a reservoir portiondisposed with the reservoir portion of said cylinder member and adaptedto receive material to be injected into said aerosol can, the upper edgeof said reservoir portion of said liner engaging said cylinder headwhereby said cylinder head retains said liner in position, a cylindricalportion of less diameter than and disposed directly below said reservoirportion of the liner and fitting closely within said main working boreand a connecting portion of less diameter than and disposed directlybelow said cylindrical portion and fitting closely within said reducedbore of said cylinder member and adapted to make sealing engagement withsaid valve body, a piston making a working fit with the interior of saidcylindrical portion of said liner and extending through the reservoirportion of said liner, and means for reciprocating said piston withinsaid cylindrical portion of said liner, said cylindrical portion andsaid connecting portion of said liner being externally supported againstinternal pressures by said cylinder member.

7. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having anupwardly projecting, normally closed discharge valve at the top thereof,said valve having a cylindrical outer surface, said apparatus comprisinga base adapted to support an aerosol can to be filled, a cylinder membersupported by said base having a main working bore communicating at itslower end with a bore of reduced diameter that surrounds the saidupwardly projecting valve of a can disposed in the apparatus, anenlarged cylindrical reservoir portion communicating with said workingbore, and a cylinder head detachably mounted on said reservoir portion,a disposable plastic liner removably disposed Within said cylindermember, said liner having a reservoir portion adapted to be disposedwithin said reservoir portion of said cylinder member, a cylindricalportion of less diameter than and disposed directly below said reservoirportion of the liner and communicating with said reservoir portion andfitting closely within the working bore of said cylinder member and aconnecting portion of less diameter than and disposed directly belowsaid cylindrical portion and fitting closely within said reduced bore ofthe cylinder member, said connecting portion having an integrally formedinwardly projecting annular rib adapted to make sealing engagementbetween said connecting portion and the cylindrical outer surface ofsaid valve, said piston having a piston rod portion that is guided bysaid cylinder head, and means for reciprocating said piston within saidcylindrical portion of said liner, said cylindrical portion and saidconnecting portion of said liner being externally supported againstinternal pressure by said cylinder member.

8. Apparatus for charging material to be sprayed into an aerosol cancontaining a liquified propellant gas under pressure, said can having anupwardly projecting, normally closed discharge valve at the top thereof,said valve having a cylindrical external surface and being openable byexternal fluid pressure substantially in excess of the pressure withinsaid can, said apparatus comprising a base adapted to support an aerosolcan to be filled, a cylinder member supported by said base, saidcylinder member having a main vertical working bore directly connectedat its lower end to a vertical bore of reduced diameter that is adaptedto surround the upwardly projecting valve of a can disposed in theapparatus, an enlarged, upwardly extending reservoir portion directly incommunication with the upper end of said main working bore and acylinder head removably mounted on the upper end of said reservoirportion, a disposable liner removably dispose-d within said cylindermember, a piston making a working fit within that portion of the linerdisposed in said working bore and having a piston rod portion extendingupwardly through and guided by said cylinder head, means forreciprocating said piston comprising a bracket secured to said base, anupwardly extending link pivoted to said bracket, an actuating leverpivoted at one end to the upper end of said link and having a hand gripat the other end, an intermediate portion of said actuating lever beingpivoted to the upper end of said pis ton, and stop means carried by saidpiston and engageable with said cylinder head to limit the upwardreciprocation of said piston to a position in which the outer surface ofsaid piston is disengaged from the upper portion of said working basewhereby to provide communication between said working bore and saidreservoir portion, the lower end of the piston engaging the :bottom ofsaid working bore at the lower end of its working stroke.

9. A disposable liner for an apparatus for injecting material intoaerosol cans, said liner comprising an integrally formed member having acylindrical portion adapted to make a working fit with a reciprocablepiston, a reservoir portion of larger cross section than saidcylindrical portion in communication with one end of said cylindricalportion and adapted to receive material to be injected into an aerosolcan, and a connecting portion of smaller cross section than saidcylindrical portion disposed at the other end of said cylindricalportion and having means for making a fluid tight connection with anaerosol can.

10. A disposable liner according to claim 9, wherein said reservoirportion, said cylindrical portion and said connecting portion all areconcentric.

11. A disposable liner according to claim 9, wherein said means formaking a fluid tight connection with the can comprises an inwardlyextending annular rib adapted to make sealing engagement with theexterior of said discharge valve.

References Cited UNITED STATES PATENTS 1,530,074 3/1925 Eckert 222 399 X1,638,456 8/1927 Pike 222326 X 1,981,508 1l/1934 Harris 222--340 X2,914,096 11/ 1959 Foresman 14120 3,187,787 6/1965 Kerr 184105 X3,299,855 1/1966 Eggert 22213 1 FOREIGN PATENTS 897,143 11/ 1953Germany. 73,225 3/ 1948 Norway.

LAVERNE D. GEIGER, Primary Examiner.

E. J. EARLS, Assistant Examiner.

1. APPARATUS FOR CHARGING MATERIAL TO BE SPRAYED INTO AN AEROSOL CANCONTAINING A LIQUIFIED PROPELLANT GAS UNDER PRESSURE, SAID CAN HAVING ADISCHARGE VALVE AT THE TOP THEREOF, SAID APPARATUS COMPRISING A BASEADAPTED TO SUPPORT AN AEROSOL CAN TO BE FILLED IN A VERTICAL POSITION, ACYLINDER MEMBER SUPPORTED ON SAID BASE, SAID CYLINDER MEMBER HAVING AVERTICAL MAIN WORKING BORE COMMUNICATING DIRECTLY AT ITS LOWER END WITHA VERTICAL BORE OF REDUCED DIAMETER THAT SURROUNDS THE DISCHARGE VALE OFA CAN DISPOSED IN THE APPARATUS, A DISPOSABLE LINER REMOVABLY SUPPORTEDWITHIN SAID CYLINDER MEMBER, MEANS FOR FORMING A SEAL BETWEEN SAID LINERAND SAID VALVE, A PISTON MAKING A WORKING FIT WITHIN THAT PORTION OF THELINER DISPOSED IN SAID MAIN WORKING BORE, MEANS FOR RECIPROCATING SAIDPISTON WITHIN SAID WORKING BORE AN A RESERVOIR PORTION DISPOSED ABOVESAID WORKING BORE AND IN DIRECT COMMUNICATION WITH THE UPPER END THEREOFFOR SUPPLING MATERIAL TO BE INJECTED INTO SAID AEROSOL CAN TO SAIDWORKING BORE, THE BOTTOM END OF THE PISTON CLEARING THE TOP OF THEWORKING BORE WHEN THE PISTON IS AT THE UPPER LIMIT OF ITS TRAVEL WHEREBYMATERIAL WILL FLOW BY GRAVITY FROM SAID RESERVOIR INTO SAID WORKINGBORE.